1. Field of the Invention
The present invention relates to elliptical machines and more particularly, to a pedal motion path adjustable elliptical trainer, which allows change of pedal motion paths.
2. Description of the Related Art
An Elliptical trainer is a stationary exercise machine used to simulate walking that moves along a smooth, elliptical path. Elliptical trainers offer a non-impact cardiovascular workout that can help you reach your health and fitness goals. The pedal motion paths of conventional elliptical trainers are constant, hence, the entire exercise will seem tedious, and will be unable to train all different muscles of the legs.
Taiwan Patent 1294294 discloses an elliptical trainer entitled “LEG-TRAINING ELLIPTICAL MACHINE”, which uses a screw rod of a slope control mechanism to control movement of a female screw member, causing the female screw member to bias a drag bar. When biasing the drag bar, the angle of a rail holder is changed relative to the floor to adjust the slope of the pedal motion paths. Further, Taiwan Patent M403355 discloses a lifting mechanism for an elliptical trainer, which uses a retractable rod of a linear actuator to adjust the angular position of a lift frame relative to the floor, thereby changing the pedal motion paths. The aforesaid two prior art patents allow control of the elevation of pedals to change the motion paths of sliding bars subject to different requirements from different users. However, the axis of rotation of each pedal is kept in parallel to the reference axis of the rotating mechanism assembly. When viewed from the top side, the left and right pedals can be simply biased in a front-rear direction. Thus, only a small part of the muscles of the legs can be trained during exercise, resulting in poor effects of exercise. In order to improve the drawbacks of the aforesaid two prior art designs, Taiwan Patent M407086 discloses an elliptical trainer, entitled “Improved structure of fitness elliptical machine”, which uses two sliding guide rails to control variation of the sliding motion path. The two sliding guide rails are formed of one single tubular member that is bent into a predetermined shape defining a parallel part and a splayed part. However, this design simply allows the machine to perform one specific motion model. If the user wishes to change the outward expansion angle, the user must purchase a different model of elliptical trainer or a different type of sliding rails, causing so much inconvenience.